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7th EFSMA – European Congress of Sports Medicine, 3rd Central European Congress of Physical Medicine and Rehabilitation, Annual Assembly of the German and the Austrian Society of Physical Medicine and Rehabilitation

Austrian Society of Physical Medicine and Rehabilitation

26.-29.10.2011, Salzburg, Austria

Estimates of repolarization dispersion in elite athletes and in sedentary healthy subjects

Meeting Abstract

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  • corresponding author presenting/speaker Zsuzsanna Major - Semmelweis University, Department of Health Sciences and Sport Medicine, Budapest, Hungary
  • Zsuzsanna Kneffel - Semmelweis University, Department of Health Sciences and Sport Medicine, Budapest, Hungary
  • Miklós Tóth - Semmelweis University, Department of Health Sciences and Sport Medicine, Budapest, Hungary
  • Gábor Pavlik - Semmelweis University, Department of Health Sciences and Sport Medicine, Budapest, Hungary

7th EFSMA – European Congress of Sports Medicine, 3rd Central European Congress of Physical Medicine and Rehabilitation. Salzburg, 26.-29.10.2011. Düsseldorf: German Medical Science GMS Publishing House; 2011. Doc11esm076

DOI: 10.3205/11esm076, URN: urn:nbn:de:0183-11esm0765

Published: October 24, 2011

© 2011 Major et al.
This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by-nc-nd/3.0/deed.en). You are free: to Share – to copy, distribute and transmit the work, provided the original author and source are credited.


Outline

Text

Objective: Although a rare event, sudden death in athletes generates great social and emotional impact throughout society, especially when the victim is a young athlete, it arises questions from the media: Would be the sport detrimental to health sudden death could be prevented? Several electrophysiological mechanisms (e.g. repolarization due to potassium channel downregulation, myocardial ischemia) and the presence of multiple factors such as benign cardiac hypertrophy developing normally in athletes (athlete’s heart), increased sympathetic activity, foods together can increase inhomogeneities in myocardial repolarization in this case, an otherwise harmless extrasystole occurring with unlucky timing may although very seldomly-elicit fatal arrhythmias. The arrhythmogenic substrates alone do not produce fatal arrhythmia [1]. The aim of this study was to analyze the repolarization dispersion (QT dispersion and transmural dispersion: Tpeak-Tend) in elite men athletes and in sedentary, healthy young men. In addition, we examined relationship between the repolarization dispersion and the left ventricular enlargement and the repolarization dispersion between the heart rate. Furthermore, we examined the early repolarization in elite men athletes and in sedentary, healthy young individuals.

Material/Methods: We studied 34 athletes (18 elite thriathlonists and 16 professional ball-game players) and 15 healthy non-athletes making no regular physical activity. The echocardiogram were performed according to the recommendation of the American Society of Echocardiography. Left ventricular measurements from the two-dimensionally guided M-mode were made from 5 consecutive heart cycles and we calculated the left ventricular mass. In the second step 5 minutes long, 12-lead resting ECG was recorded to establish the heart rate, Qt dispersion and transmural dispersion. Finally step, we examined the prevalence of early repolarization syndrome (ERS). Statistical analysis was done by using the Statistica 9.0 for the Statsoft. Significance was determined with one-way ANOVA with Tukey HSD post-hoc test. Next step we calculated the correlation between the LV mass and the QT dispersion and between the LV mass and the heart rate.

Results: In the myocardial hypertrophy (LVH) and in the resting heart rate water thriatlonists were the best and non-athletes the worst. Endurance athletes and ball-game players had a significantly greater LV mass (p<0,001) and lower heart rate (p<0,001) than healthy sedentary non-athletes. The QT-dispersion was greater in the athlete’s groups (p<0,01) than in the controls. The difference in the transmural dispersion between the groups with pathological LVH was not statistically significant (p<0,6). In the group of non-athletes and competitors of several kinds of sports (endurance athletes and ball-game-players) LVMM correlated significantly with the QT dispersion (r=0,56). We found negative correlation between the QTd and the heart rate (r=-0,36) by groups.

Conclusion: 1. Regular and extensive endurance training results in similar changes in LV and RV mass and function in athletes.

2. The measurement of QT dispersion may be an useful and non-invasive method for screening additional pathological conditions in endurance athletes.

3. Repolarization wave front starts earlier on ventricular wall and partially overcomes the end of depolarization causing an upward displacement of the J-point, ST segment elevation, and inscription of magnified T-waves amplitudes leading to characteristic surface ECG waveform patterns.


References

1.
Varró A, Baczkó I. Possible mechanisms of sudden cardiac death in top athletes: a basic cardiac electrophysiological point of rewiev. Pflugers Arch. 2010;460:31-40.